1. Field of the Invention
The invention relates generally to nonsurgical, female sterilization methods, and more particularly to an improvement in the method for inducing tubal occlusion by the transcervical application of quinacrine hydrochloride.
2. Description of the Prior Art
Demographers have warned that unless effective measures are soon taken to arrest the explosive growth in population, society as a whole faces a future of indescribable bleakness. The seriousness of this problem has been widely recognized and research programs on fertility control have been initiated throughout the world with the principal objective being to develop a safe and effective contraceptive method which is relevant to the conditions of the developing countries, since they contain nearly two-thirds of the world population.
Although the surgical sterilization of women is the most effective method of contraception known, the medical infrastructure required for carrying out such procedures on a mass basis does not exist in the evolving countries. In view of this fact, a high priority has been given to the development of a nonsurgical method for effecting sterilization which can be performed by paramedical personnel and which does not require extensive facilities or equipment.
Previous efforts to achieve this goal have included the infusion of various scarifying and necrotizing agents, tissue glues and tubal plugs into the uterus for the purpose of effecting an occlusion of the gamete carrying oviducts or fallopian tubes. However, these procedures have been abandoned because they are ineffective or are not sufficiently developed to determine their safety or effectiveness.
To date, the only nonsurgical procedure known which appears to have possibilities for effecting the sterilization of women on a mass basis is the transcervical instillation of quinacrine hydrochloride. However, despite the fact that this method offers great promise in fertility control, it has not, prior to the present invention, been sufficiently safe and effective for application on a widespread basis.
Heretofore, the quinacrine hydrochloride has been delivered in the form of a liquid suspension which places limitations on the concentration or dosage level which can be brought into the uterine cavity to achieve maximum effectiveness. Moreover, high fluid pressures often developed within the uterus following injection. The presence of this internal pressure tends to cause excessive uterine distension and carries the risk of leakage into the peritoneal cavity or circulatory system.
Although not a common occurrence, a number of cases of cortical excitation have been reported following the instillation of quinacrine in a liquid carrier. The condition is characterized by nervousness, irritability, emotional change and transient psychosis with the risk that the patient may convulse if not treated promptly. It is believed that the syndrome is due to the rapid intravascular absorption of quinacrine when it is instilled into a highly vascular area.
For a recent clinical evaluation of the procedure just described, reference may be had to a paper titled "The Clinical Efficacy of the Repeated Transcervical Instillation of Quinacrine for Female Sterilization" by J. Zipper, et al., published in Int J Gynaecol Obstet 14:499-502, 1976. The safety and efficacy of the repeated transcervical instillation of quinacrine hydrochloride in a suspension of 2 percent xylocaine was evaluated in 200 patients. All instillation procedures were performed during the proliferative phase of the menstrual cycle. The second instillation was made in the first menstrual cycle following the initial instillation and the third instillation at 6 months after the first. Follow-up visits were scheduled at six month intervals after the last instillation.
The potentially serious complications following the instillation were four cases of cortical excitation and one case of acute adnexitis. Fifty-one pregnancies were reported with forty-one occurring before completion of the three instillations. Based on the results of this study, the authors concluded that it does not appear that the intrauterine instillation of quinacrine hydrochloride is sufficiently effective for widespread use as a nonsurgical sterilization procedure.
It is, therefore, a principal object of this invention to vastly improve the effectiveness of this procedure and to reduce or eliminate the hazards associated with it.